Coleus barbatus was first described by
Henry Cranke Andrews in 1810 as
Plectranthus barbatus. Vahl's name is illegitimate, because he treats it as a synonym of the earlier described
Ocimum hadiense Forrsk. Vahl spelt the epithet as "
Forskålaei", referring to
Pehr Forsskål, whose surname is also spelt "Forskål". The
International Code of Nomenclature for algae, fungi, and plants at Art. 60.7 specifies that "å" is to be replaced by "ao". Willdenow in 1800 referred to Vahl's name, but spelled the epithet "
forskolaei". (, the
International Plant Names Index had the spelling "
forskalei".) It was probably this species that Briquet referred to when transferring a species to
Coleus as "
C. forskohlii (Willd.) Briq.", introducing yet another spelling of the epithet; however, Briquet did not explicitly refer to a
basionym. Briquet regarded "
Coleus forskohlii" as synonymous with what he called "
C. barbatus Benth.", although Vahl had originally given a different synonymy. Paton et al. (2019) state that the epithets "
forskalaei" or "
forskohlii" are incorrectly applied to this species, instead treating binomials with these epithets as synonyms of
Coleus hadiensis, in accordance with Vahl's original use. ==Distribution==